Coco O. was a welcome surprise for most folks who bought the recent soundtrack for Baz Luhrmann’s adaptation of “The Great Gatsby.” She was the highlight, one of the few artists who captured the movie’s heart while sounding like a modern singer with an old soul. As the vocalist for Quadron, the Danish duo that also includes musician-producer Robin Hannibal, Coco is a force of nature, a hopeless romantic who can also play the role of fierce dance diva. On “Avalanche,” its slinky sophomore release, the electronic soul band toes the fine line between club cuts and after-hours ballads. It feels like a bookend to “Woman,” the new album from Rhye, which makes sense given that Hannibal is also part of that band. One minute Coco is reminding you of Adele (“Crush”), the next she’s close on Jessie Ware’s heels (“Better Off,” featuring a cameo by rapper Kendrick Lamar). Sprinkled throughout are glimmers of ’70s funk and ’90s neo-soul, as heard on “Hey Love,” the album’s most unabashed and infectious moment. (Out now) JAMES REED